Notes > Colour

Colour

• Colour gamut
  • The range of possible colours in a system
• Print: Inks (reflect light)
  • CMYK
  • CMYKOG
  • Spot Colour (PMS)
• Web: Direct light
  • RGB
    

Printing Ink

• Two parts
  • Pigment or dyes for colour
  • Vehicle to adhere colour to paper
    • Usually linseed oil, soybean oil, mineral oil or petroleum
    • Further adhesion from resins or other binding agents
• $10-billion per year global industry
  • 150,000 copies of an 80-page magazine requires about 68 gallons of ink
• 1.02 million tons of ink in 2009
  • Liquid inks, water borne nincludes inks, technological varnishes, extenders, primers and overprint varnishes
  • Liquid inks, solvent borne nincludes flexo, gravure, publication gravure inks, technological varnishes, extenders, primers and overprint varnishes
  • Oil based inks nincludes coldset and heatset offset as well as conventional sheet-fed offset inks

EuPia (European Printing Ink Assoc.), 2010

• Most of the top global ink companies have been facing declining sales
  • Global recession
  • Changing nature of the printing industry.
  • Improved in first half of 2010

Ink World, 2010

Two types of printing ink

• Opaque
  • Covers colour underneath
    • Paper or ink
• Transparent
  • Lets colour through to create various colours, tints and shades.
    • Process colours
  
  

About E-ink

• It’s not really ink
• Electronic--a small circuit board with button cell batteries and two displays.
• 90-day shelf life
• Esquire had first E-Ink magazine cover in the world, October 2008 issue
  • http://www.youtube.com/watch?v=iKS12PMdJ6w (opens in a new window)

Colour

• Colour for sake of colour worse than no colour at all
  • Successful use requires correlating use with the objective of publication.

Reasons for using colour

• Eye appeal
• Attract attention
• Create mood
• Accent and contrast
• Direct reader through message
• Create identity or association
• Aid retention
  

Cost of using colour

• Cheapest use is colour paper.
• Spot colour--adding individual colours.
  • Increase impact of printed piece.
  • Usually for single graphic elements.
  • Used to emphasize illustrations, type, initial caps, or rules.

With one colour of ink, simultaneous printing of the solid colour and various tints achieved by screening: Applying colour in dots in varying size and density, Or printing type, tint blocks and art from screened negatives White of paper creates tint. Can also shade, or add black, to a solid colour.   Tinting shown from center of wheel------> Shading shown on outter part of wheel----->

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Mixing inks Inks can be premixed by the printer or manufacturer Pantone Matching System.
Inks can be mixed by printing process

Four process colours (CMYK): Cyan (a blue-green) Magenta (a red-violet) Process yellow Process black

Pantone Matching System System of colour mixtures The standard for spot colour printing. Pantone library in InDesign. Printed samples on swatches (right) show colours as they will appear on coated, uncoated papers, etc.   Back to top

Metallic inks

• May contain copper, brass (alloy of copper and zinc) and aluminum-based pigments
• Toxic or heavy metals in inks are environmental issue
  • Those in metallic inks not considered a hazard
    

Physics of colour Colour comes from sunlight Different wavelengths of light Visible part of electromagnetic spectrum Reflected ray is colour we see. RGB is primary colours of sunlight

Ink Colour values--the colour wheel 1. Primary triad (inks, reflected light, not sunlight) Red, yellow, blue Colours halfway between are secondary colours 12 hues.

Colour terminology Hue--Colour Tone--Variations of hue Value--Relative darkness, lightness of colour Shade--Adding black to darken Tint--Adding white (of paper) to lighten. Chroma, or saturation--Colour intensity pigment saturation tendency to move toward or away from gray.

• Black type on white or pale yellow is best for readability.
• One colour should dominate
  • Any other should be used for accent or contrast.
• Warm colours are higher in visibility than cool colours.
• Colour on text makes it stand out
  
  

Balance

• From proper placement of elements by weight or visual emphasis.
  • Colour adds further weight, according to hue and value.
    • When 2-colour job includes black, the colour should be given relatively little weight.
      

Rhythmic use of colour

• Achieved through repetition at points in the printed piece.
• Spots of colourcan be used
  • To guide reader's eye through the message
  • For rhythm.

Body type

• Body type in colour is rarely as good as black on white.
• Also effective (depending on objective):
  • Brown on buff
  • Dark blue or green on some shades of off-white
  • Use sparingly:
    • Best limited to occasional captions or other small areas that require special contrast

Display type

• Especially effective in colour.
• Contrast to certain words in title
  • For attention and
  • Communication value of words.

Other applications of colour

• Rules and borders
  • Can separate and draw attention to panels of text.
• Typographical dingbats
  • Get special attention through colour
• Create rhythm
  • Initial letters, stars, bullets, squares, etc.
• Surprinting colour type over illustrations.

Computr Colour Modes

• For print
  • CMYK
• For Web
  • RGB
  • 256 index colours
• Browser-safe colours
  • 216 of 256 index colours
  • On Web, value is intensity
  • Order always R,G,B
    • Indicated by values, 0-255
    • Or by percentages
    • Or hexadecimal codes, in triplets
      • 00, 33, 66, 99, cc, ff
• Unix X11 colour names
  • 140 colour names using RGB combinations used on modern computers.
    • Microsoft Windows
    • With hex triplet notations
    • Not all web-safe colours.
    • http://msdn.microsoft.com/en-us/library/system.windows.media.brushes(VS.85).aspx
• For further study: http://www.worqx.com/color/index.htm

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